These are scraps left over from our interactive LED lab coats, made for this year’s Autodesk University. The black-capped ends appear at the end of each roll, and have solid-core wires or sockets pre-soldered onto the contacts, preventing us from soldering to both ends. That was fine for me, since almost all pieces would be connected only at one end.

Here, I’ve stuck a switch into the power line and soldered together the lights for the back of the bike. To get red, solder to the 12V+ pad (labeled on the strip) and the middle remaining pad. (These things still shine gorgeously on nine volts.)

Cut the strips down to size, if needed, and use a razor to remove the epoxy covering the solder pads.

I stuck everything together using the adhesive backing on the LED strips, as well as some hot glue. All solder connections were insulated (from each other and the elements) with more hot glue. I would apply a blob to the connection(s), wait maybe 15 seconds, then roll it between my fingers to ensure that everything was covered.

Despite my apprehension, the hot glue is barely apparent, and unless you look closely, the lights integrate naturally with the bike frame. I tucked the battery and switch underneath the bike seat, to protect them from water and other damage.

I decided against running a cable down the center pole, for a couple of reasons:
• The way I normally manhandle the bike would subject the cables to lots of pulling and bashing, and
• Somewhat ridiculously, I was trying to keep this hack job unobtrusive (or even attractive).

That means a second battery and switch for the front. Even so, this system is easier to deal with than the old lights, which required some arcane combination of pushing and holding to turn them off.

Also, one side wouldn’t light up. I hadn’t realized that TechShop was closing early for New Year’s, so I fumbled with this for a little while and gave up ten minutes past closing. (Immense thanks to the good people of TechShop for not beating me out of there with a broomstick.) Turned out that end was just busted; later, I flipped it around and the other solder points worked.

I took the design down a notch to get on the road sooner. The Dymo tape is a GENIUS item! It blends beautifully with the handlebar stock and battery clip. My current setup has the battery mounted to the bottom of the stock, as you can see above, and the LED strips branch out from a Y at the front/center. I have to watch the battery, and will need some better way of holding it in. Perhaps a strip of metal tape across the clip opening. In fact, I’ll do that now.

• 2 minutes later •

I went with blue for the front, since white would require powering all three colors, red is too dim, and aesthetics ruled out green. The blue solder pad is the one furthest from power. These strips were left long, stretching the full width of the handlebars, because they look cool under my fingers and provide more light.

I thought the front lights would be very ugly, but they have a low profile. You can’t even see them when you’re behind the bike (except at night), and oh, how they shine! I can see them radiating blue onto the ground, and the red shines onto my legs, which is nice because I can easily tell whether the back light is on or off. These are far brighter than regular lights, and I feel very safe with them; at least, as safe as one should feel in rush-hour SoMa traffic. And from the shouted compliments I’ve received, San Francisco likes them, too.

<3

• ADDENDUM •

April 2013: Since this post, Felix has been stolen, and I’ve got a new steed. Tybalt has less usable handlebar space, so I’ve shortened the front lights, which detracts somewhat from the forward illumination. I’ve pointed the handlebars downward to promote ground visibility, but the smaller light chunks also made it silly to have an entire 9V dedicated to them. So, ground lighting!

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